1. Field of the Invention
The present invention relates to a motor-driven passenger seat which is installed in a passenger cabin of vehicles, such as aircraft, ships and cars, and in which positions of the seat parts, such as a seat back, a leg rest and a foot rest, can be adjusted by motor-driven actuators, and to a method for adjusting the reference positions of the seat parts.
2. Description of the Related Art
Referring to FIG. 5, a motor-driven seat installed in a passenger cabin of an aircraft will be described as an example of the motor-driven passenger seat. In a motor-driven seat 1, a seat back 3 is rotatably mounted at a rear end of a seat cushion 2, and a leg rest 4 is rotatably mounted at a front end thereof, and a foot rest 5 is mounted on the leg rest 4 in such a manner that it can be extended and retracted, as shown in FIG. 5.
The seat back 3, the leg rest 4 and the foot rest 5 are adjusted by actuators (not shown) such as electric motors, and a passenger who seats in the motor-driven seat 1 operates for example a switch or (not shown) near at hand; thus, the angle of the seat back 3 can be freely adjusted between an upright position (refer to the solid lines in FIG. 5) at which the seat back 3 is almost perpendicular to the seat cushion 2 and an almost horizontal position (refer to the dash-double-dot lines A in FIG. 5), and the angle of the leg rest 4 can be freely adjusted between a housed position (refer to the dash-double-dot line B in FIG. 5) at which it is directed vertically downward and an almost horizontal position (refer to the dash-double-dot line C in FIG. 5). Also, the foot rest 5 can be freely positioned between a retracted position (refer to the dash-double-dot line B in FIG. 5), at which the foot rest 5 is housed in the leg rest 4, and an extended position (refer to the dash-double-dot line C in FIG. 5) at which it is fully extended.
Accordingly, the seat back 3 and the leg rest 4 can be moved to the horizontal position and the foot rest 5 can be extended to the extended position; thus, the motor-driven seat 1 can be used as a bed (refer to the dash-double-dot lines A and C in FIG. 5).
In a conventional motor-driven seat 1, each actuator is provided with a limit switch to control the operation of the actuators by detecting the movement of the seat to a predetermined position limiting the range of movement of the moveable parts such as the seat back 3, the leg rest 4, and the foot rest 5 to avoid interference with other objects such as the floor 6 and to automatically obtain specific positions (such as seat position or bed position) by synchronous movement of individual seat parts.
However, the conventional motor-driven seat 1 has the following problems. In order to adjust the operating positions of the limit switches of the seat parts, it is necessary to move the actuators to proper positions and to adjust the positions at which the limit switches are mounted so as to determine the seat positions. In this instance, whether the adjusted positions are right or not is visually checked by activating the actuators again and operating the limit switches. When the adjusted positions are not right, they must be adjusted again. Since this process must be performed for each of the limit switches of the actuators, adjustment is extremely complicated.
The present invention has been made in the light of the above problems. Accordingly, it is an object of the present invention to provide a motor-driven passenger seat in which the range of movement and operating positions of the actuators can be easily adjusted, and a method for adjusting the same.
In order to achieve the above object, according to the present invention, a motor-driven passenger seat comprises: a plurality of motor-driven actuators for adjusting positions of seat parts; a position determining device for determining an operating position of the motor-driven actuator; a sensor for detecting the movement of the motor-driven actuator to an end of a stroke; and a controller for controlling operation of the motor-driven actuator in response to an input of an operation switch, based on a position determined by the position determining device, and in accordance with a predetermined reference position, wherein the controller moves the motor-driven actuator to the end of the stroke, and the sensor has an adjusting mode for adjusting the reference position based on the position determined by the position determining device when the sensor senses the end of the stroke.
In such an arrangement, a range of movement of the motor-driven actuator and a point to which the parts are synchronously moved can be changed by changing the setting of the reference position. Also, the adjusting mode is carried out and the motor-driven actuator is temporarily moved to the end of the stroke, so that the reference position to which the motor-driven actuator is controlled can be adjusted based on the position of the end of the stroke.
According to the present invention, there is provided a method for adjusting a motor-driven passenger seat comprising a plurality of motor-driven actuators for adjusting the positions of seat parts; a position determining device for determining the operating positions of the motor-driven actuators; a sensor for sensing the movement of each of the motor-driven actuators to the end of the stroke; and a controller for controlling the operation of the motor-driven actuators in response to an input of the operation switch, based on the position determined by the position determining device and in accordance with the reference positions, comprising the steps of: moving each of the motor-driven actuators to the end of the stroke; and adjusting the reference position based on the position determined by the position determining device when the sensor senses the end of the stroke.
In such an arrangement, each of the motor-driven actuators is temporarily moved to the end of the stroke, so that the reference position for controlling the motor-driven actuator can be adjusted based on the position of the end of the stroke.